<!DOCTYPE html>
<html lang="zh-CN">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>学生成绩管理系统 - 登录</title>
    <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.4.0/css/all.min.css">
    <style>
        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
            font-family: 'Segoe UI', 'Microsoft YaHei', sans-serif;
        }

        body {
            display: flex;
            justify-content: center;
            align-items: center;
            min-height: 100vh;
            background: linear-gradient(135deg, #6a11cb 0%, #2575fc 100%);
            padding: 20px;
        }

        .container {
            width: 100%;
            max-width: 450px;
            background: rgba(255, 255, 255, 0.95);
            border-radius: 16px;
            box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
            padding: 40px 35px;
            position: relative;
            overflow: hidden;
            backdrop-filter: blur(10px);
            z-index: 10;
        }

        .container::before {
            content: '';
            position: absolute;
            top: -50%;
            left: -50%;
            width: 200%;
            height: 200%;
            background: radial-gradient(circle, rgba(255,255,255,0.1) 0%, transparent 70%);
            z-index: -1;
        }

        h1 {
            text-align: center;
            color: #2c3e50;
            margin-bottom: 30px;
            font-size: 28px;
            font-weight: 700;
            position: relative;
            padding-bottom: 15px;
        }

        h1::after {
            content: '';
            position: absolute;
            bottom: 0;
            left: 50%;
            transform: translateX(-50%);
            width: 80px;
            height: 4px;
            background: linear-gradient(to right, #6a11cb, #2575fc);
            border-radius: 2px;
        }

        .form-group {
            margin-bottom: 25px;
            position: relative;
        }

        label {
            display: block;
            margin-bottom: 8px;
            font-weight: 600;
            color: #34495e;
            font-size: 15px;
        }

        .input-wrapper {
            position: relative;
        }

        input {
            width: 100%;
            padding: 14px 20px 14px 45px;
            border: 2px solid #e0e6ed;
            border-radius: 10px;
            font-size: 16px;
            transition: all 0.3s ease;
            background-color: #f8f9fa;
            color: #2c3e50;
        }

        input:focus {
            outline: none;
            border-color: #6a11cb;
            box-shadow: 0 0 0 3px rgba(106, 17, 203, 0.1);
            background-color: #fff;
        }

        .input-wrapper i {
            position: absolute;
            left: 15px;
            top: 50%;
            transform: translateY(-50%);
            color: #7f8c8d;
            font-size: 18px;
        }

        .btn {
            width: 100%;
            padding: 14px;
            background: linear-gradient(to right, #6a11cb, #2575fc);
            color: white;
            border: none;
            border-radius: 10px;
            font-size: 17px;
            font-weight: 600;
            cursor: pointer;
            transition: all 0.3s ease;
            box-shadow: 0 4px 15px rgba(106, 17, 203, 0.3);
            margin-top: 10px;
        }

        .btn:hover {
            background: linear-gradient(to right, #2575fc, #6a11cb);
            transform: translateY(-2px);
            box-shadow: 0 7px 20px rgba(106, 17, 203, 0.4);
        }

        .btn:active {
            transform: translateY(0);
        }

        .error-message {
            color: #e74c3c;
            font-size: 14px;
            height: 20px;
            margin-top: 6px;
            padding-left: 5px;
        }

        .status-message {
            padding: 15px;
            margin: 20px 0;
            border-radius: 10px;
            transition: all 0.4s ease;
            font-size: 15px;
            text-align: center;
        }

        .status-success {
            background-color: #d4edda;
            color: #155724;
            border: 1px solid #c3e6cb;
        }

        .status-error {
            background-color: #f8d7da;
            color: #721c24;
            border: 1px solid #f5c6cb;
        }

        .decoration {
            position: fixed;
            border-radius: 50%;
            z-index: 0;
        }

        .decoration-yellow {
            width: 250px;
            height: 250px;
            background: radial-gradient(circle, rgba(255,204,0,0.15) 0%, transparent 70%);
            top: 10%;
            left: 10%;
        }

        .decoration-red {
            width: 400px;
            height: 400px;
            background: radial-gradient(circle, rgba(231,76,60,0.1) 0%, transparent 70%);
            bottom: 10%;
            right: 10%;
        }

        .decoration-green {
            width: 180px;
            height: 180px;
            background: radial-gradient(circle, rgba(46,204,113,0.1) 0%, transparent 70%);
            top: 50%;
            right: 20%;
        }

        @media (max-width: 480px) {
            .container {
                padding: 30px 25px;
            }

            h1 {
                font-size: 24px;
            }

            input {
                padding: 12px 15px 12px 40px;
            }
        }
    </style>
</head>
<body>
<div class="decoration decoration-yellow"></div>
<div class="decoration decoration-red"></div>
<div class="decoration decoration-green"></div>
<div class="container">
    <h1>学生成绩管理系统</h1>
    <form id="loginForm">
        <div class="form-group">
            <label for="username">用户名</label>
            <div class="input-wrapper">
                <i class="fas fa-user"></i>
                <input type="text" id="username" name="username" required placeholder="请输入用户名">
            </div>
            <div class="error-message" id="usernameError"></div>
        </div>
        <div class="form-group">
            <label for="password">密码</label>
            <div class="input-wrapper">
                <i class="fas fa-lock"></i>
                <input type="password" id="password" name="password" required placeholder="请输入密码">
            </div>
            <div class="error-message" id="passwordError"></div>
        </div>
        <button type="submit" class="btn">登 录</button>
    </form>
    <div id="loginStatus" class="status-message" style="display:none;"></div>
</div>
<script src="index.js"></script>
</body>
</html>